The present invention relates generally to temperature displays, and more particularly to differential temperature display systems for balancing hydronic systems.
Fluid flow in complex hydronic (heating or cooling) systems, like those typically used in large buildings or groups of buildings, needs to be balanced. The goal in balancing the hydronic system water flow is to have a desired temperature change across each heating or cooling unit (fan coil, radiator, heater, hydronic chiller, etc.), consistent with the lowest total pumping resistance. It is practically impossible to predict a balanced flow prior to actual operation in hydronic systems using parallel flow to units.
Hydronic systems use “balance valves,” which are valves installed at each of the heating and cooling units that can be partially closed to increase the resistance to flow through that unit. To balance a system, a technician will measure the temperature differential across each unit and adjust the balance valve, i.e., restrict fluid flow, until a desired temperature drop is achieved.
One problem is that the technician using a standard differential thermometer only monitors temperature differential, and he does not monitor supply fluid temperature to ensure that fluid flowing through the unit (supply fluid) is at full temperature. For example, there could be a low temperature drop across the unit because there was too little supply fluid flowing to the unit. Also, the temperature display on standard hand-held meters cannot be read from a substantial distance, which makes it more difficult for the technician to read the temperature while balancing the hydronic system. Thus, a simple, easy-to-use and easy-to-read differential thermometer that also prominently displays supply temperature is needed.